diff --git a/OpenNest/Controls/PlateView.cs b/OpenNest/Controls/PlateView.cs
index 2c959ae..e6b1674 100644
--- a/OpenNest/Controls/PlateView.cs
+++ b/OpenNest/Controls/PlateView.cs
@@ -202,7 +202,7 @@ namespace OpenNest.Controls
             foreach (var part in plate.Parts)
                 parts.Add(LayoutPart.Create(part, this));
 
-            actionManager.OnPlateChanged();
+            actionManager?.OnPlateChanged();
         }
 
         public string Status